noodle: Skill for Claude Code

.agents/skills/ts-best-practices/SKILL.md

ts-best-practices is a skill for Claude Code, Codex from poteto/noodle. It costs 110 tokens per session (413 once invoked), scanned A, original, MIT.

A set of TypeScript rules for making data and program states explicit and checked by the compiler. TypeScript is a programming language that adds type checking to JavaScript.

In plain words
What is it for?
It is for writing or reviewing TypeScript with checked input validation, clear variant types, safe narrowing, exhaustive switches, and precise inferred types.
Why use it?
It reduces runtime errors caused by unchecked external data, unsafe type assertions, vague types, and unhandled variants. The rules make invalid combinations harder to represent in code.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: installed under .agents/ (shared by several agents).

This is poteto/noodle's own configuration. It tells Claude Code and Codex how to work on noodle itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything noodle configures →

Reuse

Borrowing it

Nothing to install: this file belongs to poteto/noodle. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/poteto/noodle/main/.agents/skills/ts-best-practices/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/poteto/noodle

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for ts-best-practices

README.md
[![agentmods](https://agentmods.dev/badge/skills/poteto/noodle/ts-best-practices.svg)](https://agentmods.dev/skills/poteto/noodle/ts-best-practices)
Your own site
<a href="https://agentmods.dev/skills/poteto/noodle/ts-best-practices"><img src="https://agentmods.dev/badge/skills/poteto/noodle/ts-best-practices.svg" alt="Measured on agentmods" height="20"></a>
Per session 110 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 413 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00110 $0.00413
Opus 5 $0.00055 $0.00206
Sonnet 5 $0.00022 $0.00083
Haiku 4.5 $0.00011 $0.00041

Measured 8d ago against content hash db7236ec0540, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

ts-best-practices scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 8d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.agents/skills/ts-best-practices/SKILL.md · 28 lines

What it actually says

Type Safety

This project's TypeScript policy. Apply when writing or reviewing TypeScript.

Rule Summary
No as casts Every as is a potential runtime crash. Validate at boundaries, then cast only if earned. Prefer Zod/Valibot over manual validation.
unknown over any any disables type checking for everything it touches. External data is always unknown.
Discriminated unions Model variants with a shared literal discriminant. No optional-field bags.
Narrowing hierarchy Prefer: discriminated union switch > in operator > typeof/instanceof > type guard > as
Type guards Must actually verify the claim. Name them isX or hasX. Prefer discriminant narrowing when possible.
Exhaustiveness checks Always add default: never arm to switches over discriminated unions. Use an absurd() helper to reduce boilerplate.
satisfies over as When verifying a value matches a type without widening, use satisfies to preserve literal types.
Impossible states If a bug requires asking "can this combination happen?" the type is too loose. Tighten it.

Read references/patterns.md for code examples of each rule.

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 8d ago First seen · 28 lines · 110 tokens per session scan A db7236ec0540

Subscribe to this mod's changes

ts-best-practices is a skill published in the GitHub repository poteto/noodle (269 stars, last pushed 5mo ago), licensed MIT. It adds 110 tokens to every session and 413 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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